BASIC (Beginners’ All-purpose Symbolic Instruction Code) is a programming language, but many early home computers booted directly into a BASIC interpreter instead of what we would consider an operating system by modern standards. Users could immediately start coding simple programs, or they could enter a command to load software from a cassette or cartridge. It’s a bit of a foreign concept today, as we generally only see programming language interpreters if we intentionally launch them. Still, many of use tipped our toes into computing with BASIC computers. To get his nostalgia fix, PlainOldAnders designed this awesome little BASIC computer that fits in your hand.
Anyone who went to the Hackaday Supercon back in 2018 will instantly recognize some of the inspiration for this project. All of those Supercon attendees received a very cool badge that doubled as a BASIC computer. The other major inspiration was a single-board BASIC computer based on the Microchip ATmega1284P. PlainOldAnders’ design combines those two in a small handheld BASIC computer dubbed “HAL 1284.” It runs on the ATmega1284P microcontroller, but comes in a form factor similar to the Hackaday Supercon badge, including the full QWERTY keyboard made with tactile momentary push buttons. The 4” LCD screen provides a decent amount of real estate for typing in your programs.
This little computer actually contains two microcontrollers. The ATmega1284P handles the BASIC interpreter and video output with its 128KB of programmable flash storage and 16KB of build-in SRAM. An ATmega328P, which is the same microcontroller used in the Arduino UNO, takes care of the keyboard matrix scanning. Aside from those that built into the LCD controller, the only other IC chip is an L7805 voltage regulator. Those are all soldered onto a custom PCB that was developed specifically for this project. Neither of those microcontrollers is powerful enough to produce a high-def HDMI signal, so an analog composite video output is generated instead. That means you’ll need to find an LCD screen that accepts composite video — an increasingly rare feature. HAL 1284 runs a modified version of TinyBASIC Plus, which reliably handles most of the functionality you would have had on a BASIC computer in the early ‘80s.